The invention relates to suspended ceiling construction and, in particular, to improvements in so-called three-dimensional ceilings.
Suspended three-dimensional ceilings with gentle wave-like configurations have been available for specialty applications where a dramatic or custom look is desired. Such ceilings find application in contemporary office environments, entertainment and gaming complexes, high-bay areas and retail space, for example.
The subject ceiling structures include convex (vault) and concave (valley) main grid runners or tees assembled with grid cross members in the form of cross tees or stabilizer bars. Typically, the primary purpose of three-dimensional ceilings is to provide a highly visible decorative structure. Consequently, a precision assembly is especially important so that visually distracting misalignments are avoided. A popular form of three-dimensional ceiling is a one-directional type where the lay-in panels are relatively long and where the joints between panels are not masked by visible cross ties. These one-directional systems are particularly prone to show misalignments of the grid structure and lay-in panels especially where the lay-in panels have a geometric pattern. In prior art constructions, the lay-in panels can take a skewed position on the supporting grid tee flanges. This misalignment is very visible and in severe conditions can even result in a panel falling off of a tee flange.
Installation of the main runners of a three-dimensional ceiling is more complex and requires more care than normally expended for conventional planar suspended grid ceilings. For example, considerable care is necessary in placement of suspension hanger wires so that when completed they hang relatively plumb in both directions of the grid. Achieving this condition is made difficult because the spacing between wires is variable depending on the inclination of the area of the grid being suspended. The extra time and effort involved in laying out and achieving a proper spacing for hanger wires longitudinally along the runners can detract from the time and effort spent in properly locating the lateral positions of the wires. These factors are in addition to the physical obstacles or conditions that can exist in the ceiling space which interfere with the proper spacing of the hanger wires. These problems have given rise to the need for a three-dimensional grid system that is more tolerant of imperfect suspension conditions and contributes to efforts at precisely positioning the grid ceiling structure.
The invention provides an improved three-dimensional ceiling that has self-aligning features which contribute to increased positional accuracy of both the grid and the panel members. More specifically, the ceiling system has main tees with a cross-sectional configuration that cooperates with specially proportioned lay-in panels to improve the parallelism of the grid tees as well as the parallelism of the panels to the grid tees. In one disclosed system, the main tees have a stem configured with an increased thickness at its lower edge where it joins the panel supporting flanges. Preferably, the thickness of the stem at its lower edge is at least about as large as its thickness adjacent its upper edge where it has a typically enlarged cross-sectional area or bulb for stiffening. This thickened stem geometry allows the components to be dimensioned so as to eliminate excessive lateral clearance between the tees and lay-in panels. The disclosed geometry still allows the panels to be assembled on the tees from a point above the grid without interference with the upper regions of the main tees.
The wide stem geometry of the main tees of the invention and correlated width of the lay-in panels is particularly important with one directional three-dimensional style ceilings. This style has no cross-tees at the visible lower face of the grid and, therefore, cannot rely on such structures to gauge and control the spacing between main runners at this face.
Stabilizer bars conventionally used to connect adjacent main tees together have a stepped or bridge-like construction to provide clearance for the installation of the lay-in panels. Typically, one-directional panels have their ends bent upwardly to form a flange that is used to couple with a mating end of another panel. The configuration of the stabilizer bars allows end-wise motion of the lay-in panels during installation and must be high enough above the supporting main tee flanges to allow the upwardly extending panel flanges to pass under the stabilizer bars. The somewhat complex geometric stabilizer bar configuration does not lend itself to precise control of the spacing of the lower visible faces of the main tees.
Many of the lay-in panel materials are relatively shear because of their translucence and/or perforated design. It is a practice to stagger the locations of the stabilizer bars between successive rows of main tees so that any shadow of a stabilizer bar visible through a lay-in panel is discontinuous and, therefore, less conspicuous. This practice exacerbates the difficulties in precisely positioning the main tees with the stabilizer bars since they do not stack up in a direct line.